Human sacrifice has a disconcerting and wonderful effect upon great composers, above all when it involves the supremely queasy issue of a father vowing to offer up his child: think of Britten with Abraham and Isaac, Mozart with Idomeneo and Idamante, Gluck with Agamemnon and Iphigenia, and here Handel with Jephtha and Iphis in his last oratorio.

Let's be clear: this was a Prom of world-class works by English composers, not a conservative concert of English music. Politically speaking, Elgar was one of the few on the right, but how different inwardly, speaking through the poet Arthur O’Shaughnessy and singing with his own reminiscences in The Music Makers of timeless art that outlives the fall of empires and individual fates.

After Thursday night’s concert I celebrated the Proms’ exploration of unfamiliar repertoire via the CBSO. The following evening saw the festival diving back into mainstream repertoire – as it must also do – conducted by the CBSO’s previous music director.

Let us never tire of singing the praises of the Proms, nor ever take them for granted. For two months concerts, many of which would be the highlight of any ‘normal’ week, keep coming night after night. And for all that it is a critic’s job to comment in detail and find fault where necessary, it is also helpful sometimes to step back and say: the Proms is an astonishing festival which we should be grateful to have.

So the Proms ignored the Berlioz anniversary challenge to perform his Requiem and serve up four brass bands at the points of the Albert Hall compass.

Time was, not long ago, when the very word “premiere” was enough to ensure a sizeable smattering of red plush holes in the Royal Albert Hall audience. It seemed people did not want to risk attending new works for fear they would sound ghastly. Any artform depends for its lifeblood on strong new creations and an audience for them; so it is excellent that this concert was the second in a matter of days in which the place was packed out for a Prom including brand-new pieces.

There it gleamed, the pearl in the massive oyster of Albert's colosseum: the gilded, decorated piano supplied to his Queen by Érard in 1856. Pearly in sound it was not, though often harp-like; the programme was of mostly silver works, with a gold scherzo and some wooden songs.

A clever programme, a vivid premiere, a Proms debut for an exciting young conductor and the first appearance there by Catriona Morison since she won the 2017 BBC Cardiff Singer of the World: all this provided grist to the mill for a sold-out Prom that was more than the sum of its impressive parts. 

Berlioz's most intimate oratorio certainly isn't just for Christmas – but, given its scale, is it right for the Proms? Certainly in anniversary year we'd hoped for something bigger: the Requiem, turned to mush earlier this year in St Paul's Cathedral, could have been made for the Albert Hall, with brass bands placed at the four points of the compass.

Perhaps those who came for the Argerich touch and left at the interval of this instant-sellout Prom were satisfied. After all, the legendary Argentinian pianist gave us some vintage minutes of her silk-spinning mercurialism.